As sleep related breathing disorders remain a major public health concern a greater understanding of the pathogenesis is required to develop and improve therapeutic options in the late 1970s it became known that ventilation during non rem sleep was critically dependent upon p co 2 levels in the early 1980s loop gain an engineering term used to define the sensitivity of a variable. High loop gain promote s recurrent apnea as the response to. Quantifying The Ventilatory Control Contribution To Sleep Apnoea The presence of sleep reduces controller gain relative to wakefulness and more importantly upper airway tone particularly in rapid eye movement sleep rem see fig. What is loop gain sleep apnea . Unstable ventilatory chemoreflex control quantified as loop gain is recognized as one of four key pathophysiological traits that contribute to cause obstructive sleep apnea osa. Loop gain in sleep apnea what is loop gain. Loop gain measured noninvasively from polysomnography can be influenc...